As a device for analyzing a target component contained in a biological sample (hereinafter, referred to as a specimen) such as blood, an automated analyzer is widely used which measures light intensity of transmitted light or scattered light having a single or a plurality of wavelengths obtained by emitting light from a light source to a reaction solution in which the specimen serving as an analysis target and a reagent are mixed with each other.
The automated analyzer includes a biochemical analysis device that performs quantitative and qualitative analysis of a target component contained in a biological specimen in the field of biochemical tests and hematology tests, and a blood coagulation analysis device that measures coagulation ability of blood serving as the specimen (hereinafter, referred to as a blood coagulation analysis device in some cases).
This coagulation ability of the blood includes exogenous ability by which the blood leaking out from the blood vessel coagulates and endogenous ability by which the blood in the blood vessel coagulates. Measurement items relating to the coagulation ability of the blood (blood coagulation time) include prothrombin time (PT) of an exogenous blood coagulation reaction test, activated partial thromboplastin time (APTT) of an endogenous blood coagulation reaction test, and a fibrinogen amount (Fbg) relating to overall blood coagulation reaction.
In the blood coagulation analysis device, in order to analyze any one of these measurement items, fibrin precipitated by adding a reagent for initiating the blood coagulation reaction is detected by using various methods including an optical method. In a case of using the optical method, the light is emitted to the reaction solution so as to detect a time-dependent light intensity change in the scattered light or the transmitted light from the fibrin precipitated in the reaction solution. In this manner, the blood coagulation time is calculated, based on a detected result. A blood coagulation time item requires photometric data at intervals of 0.1 seconds. Thus, the reaction is performed in a separate photometric port. If the reaction solution coagulates, a reaction container cannot be reused by cleaning. Consequently, the reaction container has to be discarded.
In addition to this blood coagulation time measurement, a blood coagulation/fibrinolysis test field also includes blood coagulation factor measurement and blood coagulation/fibrinolysis marker measurement. The latter coagulation/fibrinolysis marker is analyzed by a synthetic substrate method using a chromogenic synthetic substrate or by a latex agglutination method using a reagent containing latex particles in which an antibody is sensitized on (bound with) a surface. The blood coagulation time item includes PT, APTT, Fbg and the like. In addition to D-dimer or fibrin/fibrinogen degradation products (FDP), the blood coagulation/fibrinolysis marker item includes soluble fibrin monomer complex (SFMC) and plasmin-α2 plasmin inhibitor (PIC). The blood coagulation/fibrinolysis marker item is expected to increase in future, since there is a demand for early diagnosis/treatment of disseminated intravascular coagulation (DIC). Accordingly, it is desirable to achieve improved throughput or efficiency of the automated analyzer. The blood coagulation time measurement is usually completed within two to four minutes. In contrast, in a case where the coagulation ability of the blood is poor, the reaction time may be 6 minutes or longer. On the other hand, according to the synthetic substrate method and the latex agglutination method, the reaction time usually requires 10 minutes, and the reaction time is fixed similarly to the above-described biochemical analysis.
Incidentally, as the automated analyzer for clinical tests, a known device includes a stand-alone type that is operated as an independent device, and a modular type that is operated as a single device in which analysis units in a plurality of fields such as biochemical analysis and immunoassay analysis are connected to a specimen rack conveyance line in order to streamline laboratory work. The automated analyzer of the module type has a plurality of the analysis units that analyze the reaction solution in which the specimen and the reagent are mixed and reacted with each other. As a method of supplying the specimen to the analysis unit, a method is known in which a specimen rack accommodating a specimen container is conveyed via the conveyance line so as to be located at a specimen dispensing position of the analysis unit.
Since the plurality of analysis units are modularized and integrated with each other, advantageous effects can be expected in that a specimen management flow is improved and device management is streamlined. Therefore, various techniques have been devised in order to efficiently perform the measurement.
PTL 1 introduces a technique as follows. A conveyance order of specimen containers is variable by being associated with the throughput of each analysis unit, thereby obtaining an average analysis processing time in each analysis unit. In this manner, the analysis processing time is shortened as a system.
PTL 2 discloses a technique as follows. Based on analysis item information, a conveyance destination of a specimen rack is determined from the plurality of analysis units. The specimen rack is conveyed to the analysis unit which can quickly accept the specimen rack from the plurality of analysis units to which the same analysis item is assigned. In this manner, the analysis item is efficiently analyzed.
PTL 3 discloses a specimen processing system as follows. Based on each requested measurement item, an analysis unit having fewest measurement reservations is determined as the conveyance destination of the specimen rack.